Skeleton mast having legs circular in cross section



y 6, 1947- H. J. WOOLSLAYER ETAL 2,420,059

SKELETON MAST HAVING LEGS CIRCULAR IN CROSS SECTION Filed 001:. 50, 1945 2 Sheets-Sheet l WITNESSES:

32.1.4 "ATTORNEYS.

y 6, 1947- H. J. WOOLSLAYER ET AL 2,429,059

T HAVING LEGS CIRCULAR IN CROSS SECTION SKELETON MAS Filed Oct. 30, 1945 2 Sheets-Sheet 2 %WINSSES: M, W

they thus connect.

between the two legs it connects. this flange are bevel cut so that they converge Patented May 6, 1947 SKELETON MAST HAVING LEGS CIRCULAR IN CROSS SECTION Homer J. Woolslayer, Erwin A. Campbell, and Cecil Jenkins, Tulsa, Okla., assignors to Lee C. Moore & Company, Inc., Pittsburgh, Pa., a corporation of Pennsylvania Application October 30, 1945, Serial No. 625,572

7 Claims.

This invention relates to skeleton masts, and more particularly to those having cylindrical legs connected by cross braces welded thereto.

When such a mast has been constructed heretofore, it has been necessary that the cross braces between the legs be cut to length very accurately. Otherwise, the braces have been too long or too short for the spacing between the legs, thereby requiring the changing of that spacing or the piecing out of the braces that are too short. As it is difficult in practice, especially in the field, to accurately cut the braces, the building of such a mast often presents an annoying problem regarding bracing.

It is an object of this invention to provide a round leg welded mast in which the cross braces fit satisfactorily when out to ordinary tolerances.

In accordance with this invention a plurality of cross braces at the sides of a skeleton mast have their ends welded to the mast legs which The legs are circular in cross section, being formed from tubes or the like. Each of the braces extends crosswise between the adjoining legs with the ends of its crosswiseextending portion engaging those legs. The brace preferably is an angle bar, one of the flanges of which extends crosswise of the mast The ends of toward the center of the mast. Consequently, braces of slightly difierent lengths can be welded to the legs without any difliculty by merely moving the braces inwardly or outwardly relative to the center of the mast. Of course, the spacing between the legs does not have to be changed. In the case of horizontal braces, a reinforcing member may connect the adjacent end portions of the pair of braces welded to each leg. This member extends across the inside or back of the adjoining leg and is secured thereto, such as by welding. When the mast has four legs, as is the usual case, the minor angle between the vertical plane of each inclined end of each cross flange and a horizontal line connecting the axes of the legs engaging that flange is approximately 45. This locates the areas at which braces are welded to a leg to points substantially 180 apart.

The preferred embodiment of this invention is illustrated in the accompanying drawings in which Fig. l is a fragmentary view of one side 2 of a skeleton mast; Fig. 2 is a horizontal section taken on the line II-II of Fig. 1; Figs. 3 and 4 are vertical sections taken on the lines III-III and IVIV, respectively, of Fig. 1; and Figs. 5 and 6 are diagrams showing long and short braces welded to the cylindrical legs of a mast.

Referring to the drawings, an oil well mast or the like is formed from three or more legs I, generally four, that are held upright in spaced relation by means of horizontal and inclined cross braces 2 and 3. The two legs on the near side of a four leg mast are shown in Fig. 1. As shown in Fig. 2, the legs are circular in cross section, generally being formed from tubular members, while the braces preferably are formed from angle bars and have one flange extending crosswise of the mast with the other flange extending downwardly from the outer edge of the cross flange.

Referring now to the horizontal braces shown in Fig. 2, the opposite ends 4 of each horizontal flange 6 are cut off at an inclination to its axis so that the two ends will converge toward the center of the mast. Also, this flange is long enough to always engage the legs at points outside a vertical plane containing the axes of the two adjoining legs. Consequently, with the two legs set a given distance apart, the points on'the legs engaged by the beveled ends of the horizontal flange of the brace will be farther away from or closer to the plane just mentioned, or to the center of the mast, depending upon variations in length of the brace. Of course, in the first case the brace as a whole will be farther away from the center of the mast than in the second case, but the variations will not be great and will make no practical difference. The inner edges of the ends of the braces vertical flange 1 are welded to the legs, and the welds 8 are carried up across the ends of the horizontal flange. should be, before welding there may be a small gap between each inner edge of the vertical flange and the leg, as illustrated in Fig. 5. However, with ordinary tolerances this gap is negligible and does not interfere with proper welding of the brace to the legs.

The thermal strain on the legs due to welds 8 can be minimized by locating the welds on each leg at points approximately apart. In

If the brace is slightly longer than it order to do this when the mast has four legs, the inclination of the ends of each braces horizontal flange should be such that the minor angle between the axis of the flange and each inclined end is approximately 45, as shown in Fig. 2. If the braces have been cut to exactly the right length or longer, then their points of engagement with each leg will be 180 apart. If they are a little undersize, as shown in Fig. 6, their points of contact with the legs will be a few degrees closer together, but not close enough to make any material difference.

To reinforce the connection between the horizontal braces and the legs to make a more rigid structure, a reinforcing plate 9 may be welded to the horizontal flanges of the bracesengaging each leg. This plate rests on the horizontal flanges and extends diagonally of the mast across the inside or backside of the leg to which it may be welded.

The inclined or diagonal cross braces 3 have their inwardly extending flanges I I cut off at the ends so that they converge toward the center of the mast for the same purpose as the horizontal braces. However, due to the inclination of these braces, the minor angle between the flange ends and the axis of the flange is less than in the case of the horizontal braces. Nevertheless, the minor angle between the vertical plane of each inclined end of each cross flange II, and a horizontal line connecting the axes of the two legs engaged by that flange should be the same as the corresponding angle at the ends of the horizontal braces, preferably about 45 when the mast has four legs. The ends of the vertical flange l2 of each inclined brace are substantially parallel, but they are inclined to the axis of that flange and extend vertically along the adjoining legs to which they are welded'at 13. In case these inclined braces are not cut to exactly the correct length, they can be moved inwardly or outwardly relative to the center of the mast in the same way as the horizontal braces until their ends engage the adjoining legs in the right position.

According to the provisions of the patent statutes, we have explained the principle and construction of our invention and have illustrated and described what we now consider to represent its best embodiment. However, we desire to have it understood that, within the scope of the appended claims, the .invention may be practiced otherwise than as specifically illustrated and described.

We claim:

l. A skeleton mast comprising a plurality of legs circular in cross section, and a plurality of cross braces at the sides-of the mast welded to said legs,-each of said braces extending crosswise between the adjoininglegs with the ends of its crosswise-extending portion engaging said legs, and said ends converging toward the center of the mast, whereby braces of slightly different lengthscan be welded to the legs by varying the spacingbetween the braces and the center of the mast without changing the spacing between the legs.

2. A skeleton mast comprising a plurality of legs circular in cross section, and a plurality of cross braces at the sides of the mast-welded to said legs, each of said'braces having a flange extending crosswise between the adjoining legs with the ends of the flange engaging said legs, and the ends of each flange'converging towardthe 'center of the mast, whereby braces'of slightly differ- ,ent lengths can be weldedto the legs by varying the spacing between the braces and the center of the mast without changing the spacing between the legs.

3. A skeleton mast comprising four legs circular in cross section, and a plurality of cross braces at the sides of the mast welded to said legs, each of said braces having a flange extending crosswise between the adjoining legs with the ends of the flange engaging said legs, and the ends of each flange converging toward the center of the mast, whereby braces of slightly different lengths can be welded to the legs by varying the spacing between the braces and the center of the mast without changing the spacing between the legs, the minor angle between the vertical plane of each inclined end of each flange and a horizontal line connecting the axes of the legs-engaging the flange being approximately 45.

4. A skeleton mast comprising a plurality of legs circular incross section, a plurality of horizontal cross braces at the sides of the mast welded to said legs, each of said braces having a flange extending crosswise between the adjoining legs with the ends of the flange engaging said legs, and the ends of each flange converging toward the center of the mast, whereby-braces of slightly difierent lengths can be Welded to the legs by varying the spacing between the braces and the center of the mast without changing the spacing between the legs, anda reinforcing member connecting the adjacent-end portions of the pair of braces welded to each leg, said member extending across'the back of the adjoining leg and being secured thereto! 5. A skeleton mast comprising a plurality of legs circular in cross section, and a plurality of inclined cross braces at the sides of the mast connecting said legs, each of said braces having a flange extending crosswise between the adjoining legs with the ends of the flange engaging the legs near the outer side edge of the flange, the ends of each flange converging toward the centerof the mast, whereby braces of slightly difierent lengths can be welded to the legs 'by varying the spacing between the braces and the center of the mast without changing the spacing between the legs, .and each of said braces having an outer verticalflange the ends of which are inclinedto-its axis in order to-extend lengthwise along the adjoining legs, said vertical-flange ends being welded along their length to said edjoining legs. 7 r q 6. A skeleton -mast comprising :four legs circular in cross section, and a plurality of horizontalcrossbraces at thesidesrof the the mast connecting said legs, eachof said braces having a substantially horizontal flange extending 'crosswise between the adjoining legs with the ends of the flange having points of contact with-the legs, and theends of each fiangeconvergingtO- ward the center of the .mast,-the minor angle between the axis ofeach flange and itsconverging ends beingapproximately; 45 whereby :said points :of contact at each leg are substantially apart, and-eachbrace having an outer ver- -tical flange the ends-of which extend alongthe adjoining legs to which they are welded.

-7. A skeleton .mast comprising {our legs circular in crosssection and a plurality of horizontal and inclined bracesatthesidesolf the mast connecting said legs, each of said braces having a flange extending crosswise betweenathe adjoining legs with theends or .the flange engaging the legsnear the outer .sideedge of theflanse, the ends a of each flange converging toward the center of the mast, the minor angle between the vertical plane of each inclined end of each flange and a horizontal line connecting the axes of the legs engaging the flange being approximately 45, and each of said braces having an outer vertical flange provided with substantially vertical ends extending lengthwise along the adjoining legs, said last-mentioned ends being welded along their length to said adjoining legs.

HOMER J. WOOLSLAYER. ERWIN A. CAMPBELL. CECIL JENKINS.

6 REFERENCES CITED The following references are of record in the file of this patent: 

